"We have been relentlessly pursuing Hartwell, day and night, as he fled across the country," Chief Deputy Kenneth Deal said. "When a dangerous predator is on the loose, we don't stop. Public safety is always our main concern."

Friday afternoon, Hartwell appeared in Norfolk Federal Court and agreed to be extradited to Texas.

Hartwell has been arrested and released a handful of times since the early 90s and has shown he won't hesitate to run again. Investigators had described Hartwell as a sexual predator, with a violent history and a track record of running.

Hartwell, 51, cut his GPS ankle bracelet and walked out of a Denver halfway house, on South Federal Boulevard a week ago. He'd been living in Denver since December, but Hartwell's criminal history goes back much further.

In 1991, he was convicted of raping a child in Washington state. He picked up a pregnant hitchhiker there in 1995. The victim got away but said Hartwell tried to rape her.

"This is a guy who has a pretty dangerous past who's out there," said 9NEWS Psychologist, Dr. Max Wachtel.

Wachtel says a person's past actions can sometimes help predict their next moves. Hartwell has shown little sign of leaving his past crimes behind.

"Those are the patterns or the behaviors of somebody who probably isn't feeling or showing a whole lot of remorse," he said.

Marshals say Hartwell has failed to register as a sex offender multiple times between 2007 and 2009. He disappeared from a halfway house near Seattle in 2009 and made it to Texas before being picked up again.

"There's a very good chance he's gone, he's in another state now," Wachtel said. "He doesn't stick around, and is maybe smart enough to know, he'd get busted if he sticks around."

After serving 60 months in federal prison, Hartwell failed to register again in 2011, in Clear Creek County, Colorado. He went back to jail. He was paroled last December, under supervised release and was living in Denver until he disappeared.